常绿阔叶林壳斗科优势种植物地理特征数量分析

Quantitative analysis on the phytogeographic characteristics of Fagaceae dominant species in evergreen broad-leaved forest

以壳斗科锥属、青冈属和柯属的22个典型常绿阔叶优势种的分布资料和11项环境因子为基础,利用对应分析和典范对应分析,对这些物种的分布类型以及同环境因子之间的关系开展数量分析.根据对应分析的结果,全部物种可分为东、西两个分布类型.其中,东部类型又分为南、北两个亚类型.对应于物种的分布类型,研究区域也分为了西部、东部偏北和东部偏南三个分布区域.典范对应分析的结果表明,不同空间梯度上影响物种分布类型的主要环境因子不同.影响物种东西方向上分布的主要因子是年平均温差、最暖月平均温度、日照时数、太阳实际总辐射和干燥指数,而影响物种在南北方向上分布的主要因子是最冷月平均温度和太阳潜在总辐射.从分布区域的划分结果来看,同以往对亚热带常绿阔叶林区域的划分方案相比,东、西两个区域的划分与之相吻合,而南、北两个区域的划分则向北略有延伸.

Based on the distribution data of 22 dominant species of typical evergreen broadleaf forest of Castanopsis, Cyclobalanopsis and Lithocarpus （Fagaceae） and 11 climatic factors, the range types of these species and their relationship with environmental factors were analyzed by Correspond Analysis （CA） and Canonical Correspond Analysis （CCA）. According to the result of CA, all could be roughly classified into two range types： east type and west type. The east type could be divided into two subtypes., south and north one. In accordance with the classification of species, the study region was also divided into three range regions： west region, northern east region and southern east region. According to the result of CCA, the major environmental factors of various spatial gradients were different. In east-west direction, the seasonality in ternperature, mean temperature of the coldest month, sunshine duration, total actual solar radiation and aridity index had more effects on species distribution; while in south-north direction, the mean temperature of the coldest month and total potential solar radiation were the main limitations of the range of plants and played an important role on the northern boundary of species＇ range region. Compared with other scheme of vegetation zonation of subtropical evergreen broadleaf forest zone, the boundary between eastern and western region of this paper was similar while the boundary between southern and northern region was north-leaned slightly.